The present invention is a novel handle construction for a tennis racquet or other sports implements having a shaft. It is particularly applicable to game racquets of the type having a built-up handle wrapped by an outside gripping material, e.g. racquets for tennis, squash, and racquetball.
Tennis racquet frames include a head, which supports strings for hitting the ball, and a handle which is gripped by the player to impart the hitting stroke. The handle, which is mounted on a shaft portion of the racquet frame, customarily includes a core of wood, plastic, or other material wrapped by leather or synthetic gripping material, and is shaped to provide a firm, comfortable grip. Conventionally, the handle is built up directly on the shaft portion of the frame so that the handle and frame become, for structural purposes, a unitary member. Other game racquets have similar constructions.
Tennis racquets come in a variety of models, each of which is offered in a range of handle sizes. As a practical matter, tennis pro shops and other sporting goods retailers normally sell racquets of more than one manufacturer, necessitating a substantial inventory of tennis racquets of different manufacturers, models, and grip sizes.
Deer U.S. Pat. No. 3,547,440 and Snauwaert U.S. Pat. No. 3,638,943 recognize the inventory problem that is created by having to stock tennis racquets in multiple grip sizes. Each of these patents proposes tennis racquets having handles which are provided with special mounting constructions so that the handles may slide onto the shaft of the tennis racquet frame and be attached by screws.
Trysinsky U.S. Pat. No. 4,506,887 discloses another tennis racquet handle assembly in which the handle is separate from the frame. As in the case of Deer and Snauwaert, Trysinky proposes a rather complex construction for attaching the handle to the racquet by screws.
Tennis racquets must be capable of withstanding considerable force upon impact of the ball. Furthermore, it is critical for the handle to be securely attached to the racquet frame shaft. This is a principal reason for building the handle directly about the frame, i.e., so as to form a unitary structure. In order to achieve the same solid structure using a handle with a mechanical mounting structure and screws, as in the three proposals discussed above, it would be necessary to manufacture each of the pieces with great precision so as to produce a tight fit on the racquet shaft. This, along with the generally complex structure of these pieces, is undesirable from the standpoint of cost. Even if the handle could be solidly mounted on the racquet shaft initially, the repeated impact and vibration of striking the tennis ball might tend to loosen the handle from the frame at the stress bearing locations, e.g. the screws, over the life of the racquet.
While the aforementioned patents recognize the desirability of a tennis racquet with a separately mounted handle, none suggest a construction that is practical from a commercial and structural standpoint, and tennis racquet handles continue to be formed individually on the frame during construction of the racquet.
The present invention is a tennis racquet with a handle formed from a novel slide-on, resilient, one piece core or xe2x80x9cpalletxe2x80x9d. The pallet is formed separate from the racquet frame proper, and is thereafter force fit on the shaft portion of the frame. The pallet is preferably formed by injection molding, which makes it possible to control the dimensions and weight of the pallet more accurately.
A racquet according to the invention includes a frame with a head and a shaft portion extending therefrom. The shaft portion of the frame has an outer periphery that is uniform along a length coextensive with the handle and with top, bottom, side, and preferably diagonal outside surfaces arranged generally in an octagonal configuration. Preferably, the frame is formed of a molded tubular profile member, the opposite ends of which converge to form the shaft.
The handle is in the form of a resilient, tubular pallet with a uniform hollow interior conforming to the shape of the shaft. In the case of an octagonal shape shaft, the pallet interior has upper, lower, lateral, and angled internal surfaces arranged to define a generally octagonal configuration, and sized to conform to the top, bottom, side, and diagonal outside surfaces of the frame. Preferably, the internal surfaces are fluted with a series of longitudinally extending grooves.
The outer surface of the pallet may be molded to any desired shape. In an exemplary embodiment, the outer surface is formed as a conventional octagonal grip, with a flared butt portion.
A pallet according to the invention is further formed with an array of holes in the top, bottom, and preferably diagonal outside surfaces, that extend substantially, but not all the way, through the pallet wall toward the hollow interior. The number, size, and spacing of the holes may be varied to customize the degree of elasticity along the length of the handle and around its circumference.
The pallet is formed of a solid elastomer, e.g. thermoplastic or thermoset rubber, preferably, but not limited to a relatively soft rubber (e.g. 55-60 Shore A Durometer), rather than a foam material. Because of the holes, the material, even though a solid rubber, will have some resiliency when gripped, but because it is a solid rubber it is sufficiently firm not to twist or significantly deform when the ball is hit (i.e. is not spongy). Moreover, because the enhanced resiliency is provided by holes on the outside surface, the pallet has the characteristic of being relatively more resilient on its outside surface, in areas gripped by hand, and relatively firmer, providing greater torsion resistance, in the interior, where the pallet engages the shaft. Because in the preferred embodiment the holes are provided only in selected gripping areas, the pallet remains relatively firm in other areas, i.e. areas not containing the holes (the sides). The thermoplastic rubber not only provides a cushioned feel but also helps dampen vibrations. Also, such material has sufficient memory to keep its shape and will not break down like some elastic foams.
Preferably, the pallet is wrapped, for a better grip, with a soft flexible outer wrap, such as known cloth-backed polyurethane. Such material is very soft and is flexible enough so that when the pallet is gripped, the wrap does not significantly affect the feel of the resilient pallet. Alternatively, the pallet can be used alone as the handle.
A manufacturer may maintain separate stocks of racquets and handles, thus avoiding periodic shortages and overstocks of racquets. Alternatively, a manufacturer may supply racquets and handles, in different grip sizes, separately to retailers, where the racquet is custom finished at the point of sale.
For a better understanding of the invention, references is made to the following detailed description of a preferred embodiment, taken in conjunction with the drawings accompanying the application.